3 Blood ElementsFormed Elements: Solid elements that make up 45% of blood volume.Red Blood CellsWhite Blood CellsPlateletsPlasma: Clear fluid in which formed elements are suspended, make up 55% of blood volume.

5 Blood Properties Two important properties of blood:Viscous: Nearly 5 times more viscous (thick) than water.Osmolarity: The concentration of osmotic solution helps regulate the passage of materials into and out of the blood.

8 Formed ElementsRed Blood Cells (RBCs) aka Erythrocytes: Primary mode of transport for oxygen & carbon dioxide; make up the majority of formed elements.White Blood Cells (WBCs): Immune cells – will be discussed later!Platelets: Cell fragments that help in blood clotting.Buffy Layer: Layer of WBCs, platelets, & RBCs in the bottom of a tube of blood fresh from the centrifuge.

10 Red Blood CellsErythrocytes aka Red Blood Cells (RBCs): Blood element responsible for transporting oxygen shaped like biconcave discs.Shape allows for rapid diffusion throughout the cell due to increased surface area.Hemoglobin: Protein within the RBCs that allows for gas transportation.Iron: Metal critical for hemoglobin production & oxygen transportation.Life Cycle:2,500,000 produced per second.Just over 100 day life cycle – when worn out they lyse and are cleaned up by microphages in the spleen, liver, & bone marrow.

12 Red Blood CellsRed Blood Cell Count varies based on altitude & is measured in cells per microliter:Males: 4.7 to 6.1 million cells per microliter.Females: 4.2 to 5.4 million cells per microliter.RBCs outnumber WBCs 700 to 1.

13 HemopoiesisHemopoiesis aka Hematopoeisis: The process through which formed elements are produced.Starts with stem cells colonizing bone marrow, spleen, thymus, & liver tissue in the embryo.Myeloid Hemopoiesis: Cell production occurring in the red bone marrow after infancy.

14 Hemopoiesis Proginator Cells develop into hemocytoblasts.Hemocytoblasts form the different cells of the formed elements.Erythropoietin (EPO) hormone increases the number of blasts that will turn into RBCs.Thrombopoietin (TPO) increases the formation of platelets.

22 White Blood CellsDifferential White Blood Cell Count (Differential WBC Count): A calculation of the total number of each kind of WBC in the blood stream.Average adult has a WBC of 5,000-10,000 cells per cubic millimeter.

29 HemostasisCoagulation: The conversion of a soluble fibrinogen into an insoluble fibrin.Fibrin net formed which stops the blood loss.Procoagulants: Clotting factors produced by the liver that trigger coagulation.HIGHLY dependent on Vitamin K for clot formation.3 Steps of Coagulation:Clotting factors go through enzyme reactions via intrinsic or extrinsic pathways to form prothrombinase (enzyme).Prothrombin activator causes prothrombinase to turn prothrombin into thrombin.Thrombin converts fibrinogen to fibrin & forms a clot.

31 HemostasisClot Retraction: Tightening of the fibrin clot that pulls the edges of the blood vessel together so that the tissue may repair.Fibrinolysis: The process of clot removal after vessel repair.

33 Blood TypesAgglutinogens: Antigens on the surface of the red blood cells that can react when placed with blood of a different “type”.Two Groups of Blood Types based on Agglutinogens:ABO GroupRh Group

36 Blood TypesRh Group: Group based on one particular agglutinogen (named after rhesus monkey).Rh-Positive: Rh agglutinogens present on red blood cells.Approximately 90% of populationRh-Negative: Rh agglutinogens not present.Anti-Rh Antibodies: Formed during an initial infusion of Rh+ blood into Rh- patient; leads to hemolytic (anti-clotting) effect during future encounters with Rh+.

45 White Blood Cell DisordersLeukemia: Cancer of the blood-forming tissues. Death typically occurs from infection or excessive bleeding.Acute Leukemia: Uncontrolled production of immature leukocytes occurs.Chronic Leukemia: Accumulation of mature leukoctyes due to leukocytes not dying at the end of the normal cycle.

47 Platelet DisordersHemophilia: Clotting deficiency – typically X-linked inherited.Hemophilia A: Caused by a lack of factor VIII that is necessary for coagulation. Most common type.Hemophilia B: Caused by a lack of factor IX.

49 Platelet Disorders Thrombus: An unwanted blood clot.Embolus: An unwanted blood clot that is wandering throughout the blood vessels.Pulmonary Embolism: Blood clot in the lungs.Anticoagulants: Thrombolytic agents that can be used to reduce the possibility of clotting.Ex. Asprin, Willow bark, heparin, etc.